1. Field of the Invention
The present invention relates to a time code generator and a time code generating method, a time code reader and a time code reading method, and a video recording and reproducing device having functions of generating and reading a time code.
2. Description of the Related Art
Time codes standardized by SMPTE (Society of Motion Picture and Television Engineers, Inc.) are classified into a 24-frame system time code, a 25-frame system timed code, and a 30-frame system time code.
The 24-frame system is used for films and is compatible with a frame rate of 24 frames/sec.
The 25-frame system is used for 625/50 televisions and is compatible with 25P (25 frames/sec in a progressive mode) and 50i (50 fields/sec in an interlaced mode).
The 30-frame system is used for 1125/60 HDTVs or NTSC and is compatible with 30P (30 frames/sec in a progressive mode), 29.97P (29.97 frames/sec in a progressive mode), 60i (60 fields/sec in an interlaced mode) and 59.94i (59.94 fields/sec in an interlaced mode).
Conventionally, there exists a large number of time code generators for generating time codes in the 24-frame system, the 25-frame system and the 30-frame system and time code readers for reading time codes in the 24-frame system, the 25-frame system and the 30-frame system.
However, there has not been any time code generators for generating time codes compatible with 50P (50 frames/sec in a progressive mode), 60P (60 frames/sec a progressive mode) and 59.94P (59.94 frames/sec in a progressive mode) or any time code readers for reading such time codes.
The applicant of the present invention has developed an HDCAM-SR format (“HDCAM” is a registered trademark) as a compression format of an HDTV signal. The HDCAM-SR format allows the recording/reproduction not only in 25P, 29,97P, 50i and 59.94i but also in 59.94P.
Therefore, a time code generator or a time code reader to be included in a video recording and reproducing apparatus adopting the HDCAM-SR format is also required to be compatible with 59.94P.
Moreover, since there has not been any time codes compatible with 50P, 60P, or 59.94P, it is desirable that a time code generated by the time code generator compatible with 59.94P has interchangeability with time codes in the existing 24-frame system, 25-frame system and 30-frame system (or readable by time code readers for time codes in the 24-frame system, the 25-frame system and the 30-frame system).